This is a fun chapter in the saga that epitomizes the strengths and the weaknesses of the series as a whole.
There is an improvisational philosophy behind the writing that makes each episode a thing unto itself. It's as if the writers are coming up with their basic orientation to the theme on the fly, and are too quick to branch out in any number of directions. Here, they go for quirky comedy, and it works, especially in the skillful hands of the guest actor playing "Harry". However, it the tone doesn't really jive with what's come before, or after. Overall, there is an admirable attempt to keep the mythology consistent, but as with "Threshold", the lack of underlying structure is distracting and ultimately counterproductive.